Intrinsic Conductance of Domain Walls in BiFeO₃

Abstract

Ferroelectric domain walls are two-dimensional (2D) structural boundaries that separate regions with different orientations of electrical polarization-domains [1] , which exhibit functional characteristics that are completely different from the domains that they delineate. For example, it has been shown that they may be metallic [2] or even superconducting [3] , while the domains that they separate are insulating. Recent research shows that the domain walls can exhibit their own distinct chemistry and magnetic behavior [4-9]. These emergent characteristics have fostered the realization that the domain walls can be used as functional elements in novel nanoelectronic devices [10-13]. Here, we report observation of the intrinsic conductance of the 71° and 109° domain walls by probing the local conductance over a crosssection of the BiFeO 3 /TbScO 3 (001) thin film heterostructures. Through a combination of conductive atomic force microscopy, high-resolution electron energy loss spectroscopy and phase-field

Emergent properties at oxide interfaces controlled by ferroelectric polarization

“…The 71°DWs in the BiFO 3 / TbScO 3 (BFO/TSO) thin-film are insulating in the direction perpendicular to the surface, which is consistent with other research results, as shown in Fig. 6g, h 123,129,[132][133][134] . However, these 71°DWs are found to be conductive in [010] p direction, which is parallel to the thin-film surface, as shown in Fig.…”

Controlled Nucleation and Stabilization of Ferroelectric Domain Wall Patterns in Epitaxial (110) Bismuth Ferrite Heterostructures

“…In Figure 2b, the atomically sharp vertical domain wall in the center separates the switched domain with upward polarization from the backswitched domain with downward polarization. We note that this vertical 109° domain wall does not carry bound charges, [ 29 ] implying that such a domain wall is stable. According to the Ginzburg–Landau–Devonshire phenomenological model, in rhombohedral ferroelectrics, 71° and 109° domain walls possess the lowest energy.…”

Unexpected Giant Microwave Conductivity in a Nominally Silent BiFeO3 Domain Wall

“…Using a simplified Ginzburg–Landau model, one can show that the DW bends toward the normal direction near the surface . We note that the bending of 71° DWs near the surface of BFO thin films has been experimentally observed by TEM and PFM studies . Figure a shows the spatial distribution of P z (out‐of‐plane component of the polarization) in the cross‐section of the film, as simulated by electromechanical finite‐element method .…”